I want to set required background mode key value so that my app also works in background. Actually i want to get the user location updates when the app is in background, but
In Xcode 5, Project setting -> Target -> Capabilities -> Background modes -> check Location updates.
If you are using an earlier version of Xcode, set the background mode for Location as in the following screenshot.
You can add that key to the info.plist. If you are using Xcode 5 it's very simple. In Capabilities just turn on the Background Modes.
In Xcode 5, Select your app, then enabled background modes and select location updates
Target > Capabilities